The present invention pertains to a fluid coupling system and more particularly to a fluid coupling having a cooperative key coding system and latching mechanism, a valve biasing mechanism with corrosion resistance, and other advantageous features.
Certain manufacturing processes require the use of many corrosive and highly reactive chemicals. In the semiconductor industry, for example, some fifteen to twenty liquid chemicals are typically stored in adjacent fifty-gallon supply drums from which they are dispensed during the manufacturing process. In the usual installation, sets of separate umbilical delivery lines for various chemicals are suspended above the drums with a particular set dedicated to a particular chemical. Each set of delivery lines is connected to its associated supply drum by a fluid coupling that has one coupling member on the delivery lines and a second coupling member on the drum.
As each supply drum is emptied during the manufacturing process, a full drum is brought in to replace the empty one. Accordingly, the coupling members must be repeatedly connected and disconnected. Because of the incompatibility of the chemicals, it is critical that each set of delivery lines be connected only to its intended drum to avoid unsafe mixing and undesired contamination. Moreover, to maintain productivity, such connections and disconnections must be made quickly and routinely by production personnel.
To insure correct connection of delivery lines to their intended supply drums, chemical extraction apparatus of the type described above uses fluid couplings that incorporate matching coding elements on the coupling members. Examples of such fluid couplings and their coding devices are shown and described in the U.S. Pat. No. 4,699,298 to Grant et al. and U.S. Pat. No. 5,108,015 to Rauworth et al. A significant disadvantage of these known couplings, however, is that they cannot be as quickly connected and disconnected as is desired. Although referred to as quick-connect couplings, they use threaded parts to secure the connection. Repeated threading and unthreading of couplings over a production run consumes a significant amount of valuable time and also can produce additional delays if the threads become fouled and otherwise fail to mesh properly.
Fluid couplings that can be connected and disconnected without threading are of course available and are truly quick-connect and -disconnect couplings. Examples of known quick-connect couplings are disclosed in U.S. Pat. No. 4,436,125 to Blenkush and U.S. Pat. No. 5,052,725 to Meyer et al. Such known couplings of this type, however, are not suitable for the chemical extraction industry or other industries where matched connections are mandatory since they make no provision for coding, that is, insurance against making mismatches. Moreover, the latching mechanisms used in such known quick-connect couplings do not lend themselves to balanced and dependable two-handed operation by personnel in production processes such as described above.
In addition, the parts of such fluid couplings that contact the harsh chemicals being carried must be resistant to such chemicals. Materials such as high density polyethylene (HDPE), ethylene polymers (EPDM), or xe2x80x9cTeflonxe2x80x9d PFA are commonly used and provide excellent chemical resistance. A coil spring is the common device used to close an internal poppet valve of the type under discussion. It has been recognized that if the coil spring is made of metal, it will corrode in the presence of the chemicals. Two solutions have been used, namely, to coat the metal spring with plastic or to use any entirely plastic coil spring, but neither is satisfactory. The coated springs, coated with xe2x80x9cTeflonxe2x80x9d PFA for example, may still be vulnerable to attack if the chemical is able to penetrate the plastic. Furthermore, entirely plastic springs, again made of xe2x80x9cTeflonxe2x80x9d PFA for example, are unable to maintain the valve closed, causing leakage.
The U.S. Pat. No. 6,007,107 to Kazarian, and the co-pending application of Clancy et al., application No. 09/085,382, filed May 26, 1998 (hereinafter xe2x80x9cClancy et al. applicationxe2x80x9d), both having a common assignee with the present application, provide solutions to the problems set forth above. The present application provides alternative solutions. Each of these prior copending applications is incorporated in its entirety in the present application.
A fluid coupling system is provided including a fluid coupling having a cooperative key coding system and latching mechanism, a valve biasing mechanism with corrosion resistance, and other advantageous features. The key coding system permits interconnection of only matched coupling members while preventing the inadvertent interconnection of mismatched coupling members notwithstanding the presence of many coupling, both matched and mismatched. The coupling includes first and second coupling members that are releasably slideably, axially interfitted with their passageways in fluid communication. The key coding system includes key coding elements on the coupling members that are axially movable into matched interengagement when the coupling members are matched but are precluded from moving into matched interengagement when they are mismatched, all without rotation of the couplings or the key coding elements irrespective of the relative rotational positions of the couplings members or coding elements. The latching mechanism is movable axially and radially of the coupling members between latching and unlatching positions, again without relative rotation of the latching mechanism and coupling members. The key coding system allows the latching mechanism to move into latching position when the key coding elements match but precludes such movement when there is a mismatch. Although the key coding system and the latching mechanism do not require rotation to function, they allow relative rotation of the coupling members. Furthermore, the coupling incorporates a valve biasing mechanism that does not use a metallic spring or other corrodible parts in contact with the corrosive chemicals.
An object of this invention is to provide improvements in a fluid coupling system.
Another object is to provide a coded quick-connect and disconnect coupling for use in a chemical extraction system involving supply drums of chemicals and separate delivery lines suspended above the drums.
A further object is to improve the dependability, productivity, and safety of dispensing a plurality of incompatible chemicals through different delivery lines from different supply drums in a manufacturing process.
A still further object is to simplify the construction, reduce the manufacturing costs, and improve the overall dependability of fluid coupling systems used in chemical extraction applications.
An additional object is to provide a simplified and dependable key coding system for a fluid coupling.
Another object is to provide a simplified and dependable latching mechanism for fluid coupling that uses a key coding system.
A further object is to avoid the corrosive effects of harsh chemicals on a fluid coupling used to handle the chemicals.
Yet another object is to provide a more dependable closure mechanism for the poppet valve in a fluid coupling wherein the closure mechanism is not made of materials that corrode in the presence of harsh chemicals while providing a dependable seal that does not leak.
Another object is to provide an interactive key coding system and latching mechanism in a fluid coupling wherein the coupling members cannot be coupled and latched unless they match.
Still another object is to provide a fluid coupling for fluid carrying lines that does not require threading or unthreading or rotation of the parts, and thus twisting of the lines, to couple, uncouple, latch or unlatch the coupling members but which allows relative rotation of the coupling members.
An additional object is to provide a coupling that includes coupling members, a key coding system, and a latching mechanism that can operate with only axial and radial motions of the parts.
Another object is to minimize the time required dependably to connect and disconnect matched coupling members of a coded coupling or to determine that the coupling members are mismatched and will not couple.
An additional object is to provide a key coding system for a coupling that can handle many different combinations of matches and mismatches.
A further object is to provide a resiliently yieldable biasing mechanism for the poppet valve in a fluid coupling that can be exposed to harsh chemicals without corroding.
Still another object is to provide a resiliently yieldable biasing mechanism for a poppet valve that does not use metal or other corrodible materials in its construction.